Method of manufacturing a green light-emitting gallium phosphide device

Abstract

A method of manufacturing a green light-emitting gallium phosphide device which comprises the steps of preparing a liquid-phase epitaxial solution of one conductivity type containing a high concentration of nitrogen at a higher temperature than 1000 DEG C; bringing said epitaxial growth solution now cooled to 600 DEG C to 1000 DEG C into contact with a gallium phosphide substrate of the same conductivity type as said solution; cooling said epitaxial growth solution to form a liquid-phase epitaxial layer on said substrate; and forming a region in close proximity to said liquid-phase epitaxial layer with the opposite conductivity type thereto.

What we claim is: 
     
       1. A method of manufacturing a green light-emitting gallium phosphide device which comprises the steps of adding nitrogen from a nitrogen compound to a liquid-phase epitaxial solution maintained at a higher temperature than 1030°C; precooling said solution to a temperature of 600° to 1000°C; bringing said precooled solution into contact with a substrate of gallium phosphide having the same conductivity type as said solution; cooling said solution for the formation of a nitrogen-containing liquid-phase epitaxial layer on said substrate; and forming a region in close proximity to said epitaxial layer with the opposite conductivity type thereto. 
     
     
       2. A method according to claim 1 wherein the nitrogen compound is one selected from the group consisting of ammonia, GaN, PN, P 2  N 3  and P 3  N 5 . 
     
     
       3. A method according to claim 1 wherein nitrogen is added to the epitaxial solution maintained at a temperature of 1030° to 1100°C. 
     
     
       4. A method according to claim 1 wherein said epitaxial solution is brought into contact with the substrate at a temperature of 900° to 1000°C. 
     
     
       5. A method according to claim 1 wherein a layer having the opposite conductivity type to the epitaxial layer already formed on the substrate is superposed on the latter layer by the process of liquid-phase epitaxy. 
     
     
       6. A method according to claim 1 wherein a layer having the opposite conductivity type to the epitaxial layer already grown on the substrate is formed in the latter layer by the process of diffusion. 
     
     
       7. A method of manufacturing a green light-emitting gallium phosphide device which comprises the steps of adding nitrogen from a nitrogen compound to an n-type liquid-phase epitaxial solution maintained at a temperature of 1030° to 1100°C; precooling said solution to a temperature of 900° to 1000°C; bringing said precooled solution into contact with an n-type substrate of gallium phosphide; cooling said solution for the formation of a nitrogen-containing n-type liquid phase epitaxial layer on the substrate; and superposing a p-type liquid-phase epitaxial layer on said n-type epitaxial layer.